Mercury and Glass

An example of how Mercury will form beads when on glass, instead of adhering to it

I was running a low fever today, and as I was checking my temperature with the thermometer, I became aware that the mercury inside doesn't stick to the glass. This is because the mercury atoms stick together due to cohesion.  This force of cohesion is greater than the force of adhesion between mercury and the glass, thus causing them not to "stick" (or not letting the mercury wet the glass) because the contact area between the two is kept to a minimum.  This also causes mercury to form a meniscus that curves upward inside the thermometer, instead of one that curves downward, like water would do.